1. Field of Invention
The invention relates to intravenous (IV) fluid flow control and more particularly to an automatic IV fluid flow control device with improved characteristics.
2. Description of Related Art
There are many devices known for controlling the flow of IV fluids to a patient. For example, U.S. Pat. No. 6,569,116 discloses an IV flow controlling device disposed in a drip chamber having an exit in a bottom, the flow controlling device comprising a flexible float member having a specific gravity less than one and an outer diameter smaller than a diameter of the drip chamber, the float member including an open upper portion and a hemi-spherical bottom portion, a wall thickness of the hemi-spherical bottom portion being thinner than a wall thickness of the upper portion of the float member, wherein the float member is submerged as fluid fills the drip chamber, fluid flowing through the exit of the drip chamber causing the float member to fall, thereby stopping fluid flowing through the exit when the flexible bottom portion of the float member blocks the exit of the drip chamber when fluid in the drip chamber is used up.
However, the prior IV flow controlling device suffers from a number of disadvantages. In detail, the device can work well when it is disposed vertically. Unfortunately, it may be inclined or may be permanently deformed due to compression. Thus, the float member may malfunction. In often times, the flexible bottom portion of the float member cannot block the exit of the drip chamber when fluid in the drip chamber is used up. Thus, the need for improvement still exists.